1. Field of the Invention
The present invention provides a coil module with a thin-profile design.
2. Descriptions of the Related Art
As passive electronic components, coil modules have been widely used in various electronic products to provide the filtering, energy storage, energy releasing and functions of the like, by converting electric energy into magnetic energy or vice versa, thereby, stabilizing the output current. In conventional technologies, a coil module (not shown) comprises a circular core 10 as shown in FIG. 1 (a cross-sectional view of the circular core 10 is shown in FIG. 1) and at least one winding (not shown) wound around the circular core 10. The circular core 10 of the conventional coil module typically has a rectangular cross-section 13, so that the inner circular portion 12 and outer circular portion 11 of the circular core 10 have the same height H0. Because an outer perimeter corresponding to the outer circular portion 11 is greater than the inner perimeter corresponding to the inner circular portion 12, the winding density in the inner circular portion 12 of the circular core 10 is greater than that in the outer circular portion 11 of the circular core 10 when the winding is wound around the circular core 10. As the turn number of the winding wound around the circular core 10 increases, the winding density in the inner circular portion 12 of the circular core 10 will become more compact, and possibly result in a plurality of winding layers in the inner circular portion 12 of the circular core 10. The increase in winding layers causes an increase in the height corresponding to the inner circular portion 12 of the coil module. This is especially true when the winding has a large wire thickness and the difference between the outer perimeter and the inner perimeter is excessively large.
Because most electronic products today are evolving towards a lightweight, thin-profile, and miniaturized design, conventional coil modules can no longer satisfy this demand. An increase in the height corresponding to the inner circular portion 12 of such a coil module would have a significant adverse influence on the overall volume of the coil module, making it impossible to install such a conventional coil module in miniaturized and thin-profile electronic products.
In view of this, efforts still have to be made to provide a coil module with a thin-profile design adapted to effectively reduce the overall volume of the coil module so that the coil module may be used in various miniaturized electronic products.